这里不会涉及一些mysql数据库安装之类的知识，但是会将自己学习以及使用mysql一些最常用的mysql语句总结到本篇文章，作为自己的学习记录和笔记。基本的环境为CentOS 6.5 数据库为mysql5.6.30。
1、启动和停止Mysql服务
1、 /etc/init.d/mysql restar #重启
2、 /etc/init.d/mysql stop #停止
3、 /etc/init.d/mysql start #启动
4、 /etc/init.d/mysql reload #平滑重启
5、 service mysql reload #平滑重启
6、 service mysql stop #停止
7、 service mysql start #启动
2、加入开机自启动
chkconfig mysql on #加入开机自启动
chkconfig --list |grep mysql 检查设置的开机自启动
3、连接数据库
mysql -h -P -u root -p -e
参数：
-h 要连接的主机
-P 数据库的端口 默认是3306 没更改的话可以不用写
-u 要连接数据库的用户名
-p 密码 可以直接无空格的加在-p参数后面，但是这种方法，在别人查看你的历史命令时
，会获得你的密码不×××全，一般是连接的时候，回车输入密码。
-e 你可以输入mysql语句但是不会进入客户端。
4、查看基础信息
select user(),version(),database(),now(); # 查看当前用户、版本、
当前数据库、当前时间等信息
mysql> select user(),version(),database(),now();
+----------------+-----------+------------+---------------------+
| user() | version() | database() | now() |
+----------------+-----------+------------+---------------------+
| root@localhost | 5.6.30 | NULL | 2016-06-16 10:08:01 |
+----------------+-----------+------------+---------------------+
1 row in set (0.11 sec)
5、为root设置密码与设置密码
mysql数据库是默认给root没有设置密码的，本次实验数据库rpm包安装的，有初始密码，mariadb在初始化的时候提示我们输入密码。
cat /root/.mysql_secret
# The random password set for the root user at Sun Jun 12 22:02:31 2016 (local time):
nR7PKQyH5DU2zjKM 这一部分为初始密码，
mysqladmin -u root password '******' #设置密码
更改密码
select host,user,password from mysql.user ;
+-----------------------+------------+-------------------------------------------+
| host | user | password |
+-----------------------+------------+-------------------------------------------+
| localhost | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| localhost.localdomain | root | *47F6BC7F709C7CCFCB1EAF451FFE6D89F1377D84 |
| 127.0.0.1 | root | *47F6BC7F709C7CCFCB1EAF451FFE6D89F1377D84 |
| ::1 | root | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| 192.168.1.% | tomcat | *6FDD34EE54803B8CC847CC5D7158702BCC21FCF6 |
| % | winnerlook | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
+-----------------------+------------+-------------------------------------------+
（1）mysqladmin -u用户名 -p旧密码 password "******"
例如： mysqladmin -u winner password "123" -p
[root@localhost ~]# mysqladmin -u winner password "123" -p
Enter password:
Warning: Using a password on the command line interface can be insecure.
（2）登陆到数据库后用set password命令
格式：SET password for user@host =password("")；注意加密函数
例如：
set password for root@'::1' =password("123");
Query OK, 0 rows affected (0.05 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> set password for tomcat@'192.168.1.%' =password("123123");
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
（3）登陆后用update直接操作user表
注意：这里要使用加密函数以及限制条件，不注意限制条件有可能会更改所有的用户密码。如下面的内容
直接更改所有的内容以及明文密码。
update user set password=("123123");
Query OK, 6 rows affected (0.03 sec)，
Rows matched: 6 Changed: 6 Warnings: 0
mysql> select host,user,password from mysql.user ;
+-----------------------+------------+----------+
| host | user | password |
+-----------------------+------------+----------+
| localhost | root | 123123 |
| localhost.localdomain | root | 123123 |
| 127.0.0.1 | root | 123123 |
| ::1 | root | 123123 |
| 192.168.1.% | tomcat | 123123 |
| % | winnerlook | 123123 |
+-----------------------+------------+----------+
正确更改的方式：
update user set password=password("123123");
Query OK, 6 rows affected (0.02 sec)
Rows matched: 6 Changed: 6 Warnings: 0
mysql> select host,user,password from mysql.user ;
+-----------------------+------------+-------------------------------------------+
| host | user | password |
+-----------------------+------------+-------------------------------------------+
| localhost | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| localhost.localdomain | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| 127.0.0.1 | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| ::1 | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| 192.168.1.% | tomcat | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| % | winnerlook | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
+-----------------------+------------+-------------------------------------------+
6 rows in set (0.00 sec)
使用where字句 添加限制条件
mysql> update user set password=password("123") where user='tomcat';
Query OK, 1 row affected (0.05 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select host,user,password from mysql.user ;
+-----------------------+------------+-------------------------------------------+
| host | user | password |
+-----------------------+------------+-------------------------------------------+
| localhost | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| localhost.localdomain | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| 127.0.0.1 | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| ::1 | root | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
| 192.168.1.% | tomcat | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| % | winnerlook | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 |
+-----------------------+------------+-------------------------------------------+
6 rows in set (0.00 sec)6、 刷新权限
mysql> flush privileges;
Query OK, 0 rows affected (0.14 sec)
7、mysql 客户端技巧
echo "select * from tb_emp8;" |mysql -u root -p test_db >>test.txt
[root@localhost ~]# echo "select * from tb_emp8;" |mysql -u root -p test_db >test.txt
Enter password:
[root@localhost ~]# cat test.txt
id names deptId salary
1 Lucy NULL 1000
2 Lura NULL 1200
3 Kevin NULL 1500
4 Lucy NULL 1000
5 Lura NULL 1200
6 Kevin NULL 1500
7 Lucy NULL 1000
8 Lura NULL 1200
9 Kevin NULL 1500
10 Lucy NULL 1000
11 Lura NULL 1200
12 Kevin NULL 1500
13 Lucy NULL 1000
14 Lura NULL 1200
方法2
mysql -u root -p -e "select * from test_db.tb_emp8;">test2.txt
Enter password:
[root@localhost ~]# cat test2.txt
id names deptId salary
1 Lucy NULL 1000
2 Lura NULL 1200
3 Kevin NULL 1500
4 Lucy NULL 1000
5 Lura NULL 1200
执行sql文件的方法
（1）mysql -u root -p test_db < /root/test.sql
（2）cat /root/test.sql |mysql -u root -p test_db
（3）登录数据库后source 加载
8、创建交互文件日志 可以用来评估和考量操作过程中出现哪些操作，可以用tee
mysql --tee=test.log -u root -p # 创建一个test.log日志文件
Logging to file 'test.log'
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 34
Server version: 5.6.30 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> \T test.log #开始记录日志文件
Logging to file 'test.log'
mysql> select user(),version(),now();
+----------------+-----------+---------------------+
| user() | version() | now() |
+----------------+-----------+---------------------+
| root@localhost | 5.6.30 | 2016-10-07 17:14:25 |
+----------------+-----------+---------------------+
1 row in set (0.11 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| booksdb |
| company |
| mysql |
| performance_schema |
| sakila |
| team |
| test |
| test_db |
| winner |
| world |
+--------------------+
11 rows in set (0.00 sec)
mysql> \t #结束记录
检查日志文件：
[root@localhost ~]# cat test.log
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 34
Server version: 5.6.30 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> \T test.log
mysql> select user(),version(),now();
+----------------+-----------+---------------------+
| user() | version() | now() |
+----------------+-----------+---------------------+
| root@localhost | 5.6.30 | 2016-10-07 17:14:25 |
+----------------+-----------+---------------------+
1 row in set (0.11 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| booksdb |
| company |
| mysql |
| performance_schema |
| sakila |
| team |
| test |
| test_db |
| winner |
| world |
+--------------------+
11 rows in set (0.00 sec)
mysql> use world;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+-----------------+
| Tables_in_world |
+-----------------+
| city |
| country |
| countrylanguage |
+-----------------+
3 rows in set (0.00 sec)
mysql> desc city;
+-------------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+----------+------+-----+---------+----------------+
| ID | int(11) | NO | PRI | NULL | auto_increment |
| Name | char(35) | NO | | | |
| CountryCode | char(3) | NO | | | |
| District | char(20) | NO | | | |
| Population | int(11) | NO | | 0 | |
+-------------+----------+------+-----+---------+----------------+
5 rows in set (0.51 sec)
mysql> select count(*) from city;
+----------+
| count(*) |
+----------+
| 4079 |
+----------+
1 row in set (0.00 sec)